Testing-circuit for measured-service apparatus.



I. DAVIDSON, In. TESTING CIRCUIT FOR MEASURED SERVICE APPARATUS.

APPLICATION FILED JUNE 22,1917- 1 ,245,32 1 Patented Nov. 6, 1917-.

Marylin/a] Ov-l INVENTOR ATTO RN EY .with an operators cord circuit.

1 UNITED s rarns mnr orrron JO HN DAVlD S ON, ;R.,..oanom mu new JERS Y, AssIeNon TO AMERicArI' irnLnrnonjnfi-gnn .m ea esjcbneaaa a; ooitronarioivfor' NEW YORK.

TEsTme-cmcuir m ivrn'asuann-snnvxoa APPARATUS.

To. all whom it may concern:

Be it known that 1, JOHN DAVIDSQN, Jr., residing at Montclair, in the county ofEsseX and State of New Jersey, have invented certain Improvements. in, Testing-Cireuits for h/Ieasured-Service.Apparatus, of which the following is a specification.

This invention relates to testing apparatus and more particularly. to equipment for testing the various, apparatus. associated It is one of theobjectsof. this invention to provide a testingequipment, which, when associated with a cord circuit, will determine whether th'ecoin collect and coin, re-

' turn. equipment of the cord circuit is. functioning properly, Another object of this invention is to provide a. testing equipment,

which, when associatedwith a cord circuit,

will determine whether the coin register equipment of thecord circuit. is functioning properly. Other and further objects of the invention will be clear. from the detailed descriptionto be given later. 7 a

In the usual type of switchboard it is oftenfound desirable to test apparatus associated with the operators cord circuit, such as. coin return or coin collect apparatus, without connecting the cord circuitdirectly to apparatus in actual service, such as a coinbox at aJsubscribers station. For this purpose it is found desirable. as shown in I this. invention to provide the switchboard with special jacks leading to. apparatus adapted to simulate the operation. of equipment which the apparatus associated with the cord. circuit would be connected with in practical service. i I

In the drawing is shown one of these special jacks, J connectedto a. testing apparatus adapted to simulate the operation of an ordinary coin box; In this testing apparatusis shown anordinary relay 3 and a polarized relay 1 having its armature normallybiased' to its neutral position. When the polarized relay 4 is actuated by a current of one polarity it; serves to throw its armature so as to close a circuit through the resistance9 directly to, ground and when actuated by current of an opposite polarity serves to throw its'armature so as to close a circuit through the resistance 9 to an interrupter 5 and" ground. The resistance 9 serves to prevent the relay 4 from becoming short circuited upon the actuation of relay Specification of Letters Patent.

PatcntedNov. 6, 191

Application filed m -22, 1917. se ia no. 17e,31o,

4. Associated with the polarized relay. 4 isaresistan'c e 8 ofsuch a valuethat apotential causing a current flow therethrough toactuate therelay 4 will be sufiicientto actuate a coin control apparatus; Connected to the sleeve. contact o'fjaclr J is aresistance 14 Ora value adapted to simulate the resistan ce. of the customary message register apparatus, An inductance. 15, a resistance 16 and. a capacity 17 are provided in 'the testing apparatus to simulate an ordinary j subscribefls line.

In, the cir uit leading from. the plug P is shown the usual apparatus associated with anordinary operators cord. circuit, Asfis.

well lrnown and in accordance with the common practice, the operation of the key K controls the action of a marginal relay 1 with which is, associatedv a source of negative potential. offsuitable voltage, for. example 110 volts, for operatingthe ordi-' nary coin return apparatus of a'coin box. Iheoperation of the key K controls the action of a marginal relay 2 with which is associated a source of positive potential of. suitable voltage, as for exa1nple11O volts,' foroperating the ordinary coin. collect apparatus of a coin boX. Under control; of the lower make. contact of the key K is a registerrelay IO-with which is associated a soi irc e of positive potential of suitable voltage, for example 39 volts, for operating the ordinary message register apparatus. Under control of either marginal relay 1 or marginal relay .2 is a signal lamp 6. Under control v of the register relay l0'is a signal lamp l2.

If the cord circuit isnow associated with the testing apparatus by insertingv the plug P into the jack J and the key K is operated the proper functioning of the coin return apparatus of the cord. circuit willbe indicated by the glowing of the signal lamp 6. If the plug P is inserted in the jack J and the key K is operatedthe proper func tioning of the coin collect apparatus of the cord circuit will be indicated by the flashing of the signal lamp 6 and the proper functioning of the message register apparatus of the cord circuit will be indicated. by the. glowing of the signal lamp 12.

With this brief description of the apparatusin mind the invention may now be more. fully understood from a description of the operation. i

To test the coin return apparatus of the cord circuit, the plug P is inserted into the jack J and the coinreturn key K, is operated, thereby applying a negative potential of 110 volts tothe tip strand of the cord over a circuit from the 110 volt source, winding of relay 1, upper make contact of key K tip contacts of plug P and jack J, winding of relay 3, windings of polarized relay 4, resistance 8 to ground. Upon the proper functioning of the negative potential source and the closing of the above described circuit the polarized relay 4 will become energized and close its upper contact. Relay 3 will also become energized and pulls up its armature to close contact 7, whereby a shunt about relay l will be closed over contact 7, low resistance 9, upper armature and contact of relay 4: to ground. This shunt will reduce the total resistance of the circuit in a manner similar to that of an actual coin apparatus so that the current flow through relay 1 will be increased sutfi-, ciently to energize this relay, which is marginal, and cause it to pull up its armature and close the circuit through the signal lamp'6. The operation of the signal lamp serves to indicate the proper, functioning of the coin return apparatus.

To test the coin collect apparatus of the cord circuit, the plug P is inserted into the 7 jack J and the coin collect key K is operated to apply a positive potential of 110 volts to the tip. strand of the cord, over a circuit from a 110 volt source, winding of relay 2-, upper make contact of key K upper normal contact of key K tip contacts of plug P and jack J, winding of relay 3, winding of polarized relay 4, resistance 8 to ground. The closing of this circuit causes relay 4 to become energized and to close its lower contact. Relay 3 is also energized and pulls up its armature to close contact 7, whereby a shunt about relay I will be intermittently closed through contact 7, resistance 9, armature and lower contact of .relay 4:, to interrupter 5 and ground. This shunt willso reduce the total resistance in the circuit in a manner similar to that of the actual coin apparatus that the current now through relay 2 will be sufliciently increased to energize said relay, which is marginal. V Theenergization of relay 2 serves to close a circuit through the signal lamp 6, which due to the interrupter 5 will be caused to flash, thus indicating that the coin collect apparatus is functioning properly.

To test the message register apparatus of the cord circuit the plug P is inserted into the jack J and the key K is operated'thereby closing a circuit from a 39 volt source, winding of relay 10, lower make contact 13 of key K sleeve contacts of plug P and jack J, through resistance 14 to ground. The resistance 14 is of such value that a potential causing a sufiicient current flow therethrough to operate the magnet 10 must be of sufficient value to operate a message register over the sleeve contact of an actual line. The closing of the circuit will cause the register relay 10 to become energized and thereby cause a circuit to be closed through the signal lamp 12, thus indicating that the message register apparatus is functioning properly.

\Vhile the invention has been disclosed as embodied in certain specific arrangements, it is to be understood that this embodiment may be widely varied without departing from the spirit of the invention as defined in the appended claims.

What is claimed is:

'1. In a testing system, the combination with a telephone'cord circuit and its associated apparatus including a marginal relay, a source of current therefor. and a'signal controlled by said relay; of a local test circuit including a resistance; means for connecting said marginal relay through a talking conductor of said cord circuit'to said test circuit; and automatically operated means included in said test circuit for shunting said resistance and thereby varying the current flow through said marginalrelay. I

2; In a testing system, the combination with a telephone cord circuit and its associated apparatus including a key associated therewith for, controlling the application of measured service controlling current; of a local test circuit; means for associating said cord circuit by means of its talking cona source of'current therefor and a signal controlled thereby; of a local test circuit adapted to simulate the resistance ofan ordinary coin box apparatus; means for connecting said marginal relay through said cord circuit to said test circuit and relay means included in said test circuit and operative, only when said source of current is of sufficient value to operate an actual coin control, apparatus, for varying the resistance of said test circuit and thereby varying phe current flow through said marginal re- 4. In a testing system, the combination with a telephone cord circuit and its associated apparatus including keys for controlling the application of measured service current; of a local test circuit comprising a high resistance circuit including a polarize'd relay, a lower resistance shunt circuit 0 and an interrupter; means for associating said cord circuit With said test circuit; means associated With said polarized relay and actuated upon the operation of one of said controlling keys for closing said shunt circuit through said interrupter and actuated upon the operation of the other of said controlling keys for closing said shunt circuit Without interruption.

5. In a testing system, the combination with a telephone cord circuit and its associated apparatus including a plurality of marginal relays, sources of measured service current therefor, and signals controlled thereby; of a local test circuit including a polarized relay With its armature normally biased to a neutral position, a resistance associated therewith and adapted to simulate the resistance of the coin control apparatus of an ordinary coin box; means for connecting said marginal relays through said cord circuit to said test circuit, whereby said sources of measured service current Will operate said polarized relay; means under the control of said polarized relay for shunting said resistance and thereby Varying the current flow through said marginal relays; and means for indicating the action of said relays.

In testimony whereof, I have signed my name to this specification this 19th day of June, 1917.

JOHN DAVIDSON, JR.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

